<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script>
			var num1 = 10;
			var num2 = '2';
//			做减法时,遇到数字类型的字符串.会将其转化为数字,然后在计算
			console.log(num1-num2);
			var num3 = '20';
			console.log(num3-num2);
			
		</script>
	</head>
	<body>
		
	</body>
</html>
